chamilo-lms2/main/inc/lib/exercise.lib.php

<?php
/* For licensing terms, see /license.txt */
/**
 * Exercise library
 * @todo move this in exercise.class or question.class depending of the functions.
 *
 * shows a question and its answers
 * @package chamilo.exercise
 * @author Olivier Brouckaert <oli.brouckaert@skynet.be>
 * @version $Id: exercise.lib.php 22247 2009-07-20 15:57:25Z ivantcholakov $
 * Modified by Hubert Borderiou 2011-10-21 Question Category
 */
/**
 * Code
 */

use ChamiloSession as Session;
class ExerciseLib
{

    /**
     * @param int $exe_id
     * @return array
     */
    public static function get_exercise_track_exercise_info($exe_id)
    {
        $TBL_EXERCICES = Database::get_course_table(TABLE_QUIZ_TEST);
        $TBL_TRACK_EXERCICES = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $TBL_COURSE = Database::get_main_table(TABLE_MAIN_COURSE);
        $exe_id = intval($exe_id);
        $result_array = array();
        if (!empty($exe_id)) {
             $sql = "SELECT q.*, tee.*
                    FROM $TBL_EXERCICES as q
                    INNER JOIN $TBL_TRACK_EXERCICES as tee
                      ON q.iid = tee.exe_exo_id
                    INNER JOIN $TBL_COURSE c
                      ON c.id = tee.c_id
                    WHERE tee.exe_id = $exe_id
                    AND q.c_id = c.id";

            $result = Database::query($sql);
            $result_array = Database::fetch_array($result, 'ASSOC');
        }
        return $result_array;
    }

    /**
     * Validates the time control key
     */
    public static function exercise_time_control_is_valid($exercise_id, $lp_id = 0, $lp_item_id = 0, $course_id = null, $session_id = null)
    {
        if (!$course_id) {
            $course_id = api_get_course_int_id();
        }
        if (!$session_id) {
            $session_id = api_get_session_id();
        }
        $exercise_id = intval($exercise_id);
        $TBL_EXERCICES = Database::get_course_table(TABLE_QUIZ_TEST);
        $sql = "SELECT expired_time FROM $TBL_EXERCICES WHERE c_id = $course_id AND iid = $exercise_id";
        $result = Database::query($sql);
        $row = Database::fetch_array($result, 'ASSOC');
        if (!empty($row['expired_time'])) {
            $current_expired_time_key = ExerciseLib::get_time_control_key($exercise_id, $lp_id, $lp_item_id, $course_id, $session_id);
            if (isset($_SESSION['expired_time'][$current_expired_time_key])) {
                $current_time = time();
                $expired_time = api_strtotime($_SESSION['expired_time'][$current_expired_time_key], 'UTC');
                $total_time_allowed = $expired_time + 30;
                //error_log('expired time converted + 30: '.$total_time_allowed);
                //error_log('$current_time: '.$current_time);
                if ($total_time_allowed < $current_time) {
                    return false;
                }
                return true;
            } else {
                return false;
            }
        } else {
            return true;
        }
    }

    /**
      Deletes the time control token
     */
    public static function exercise_time_control_delete($exercise_id, $lp_id = 0, $lp_item_id = 0)
    {
        $current_expired_time_key = self::get_time_control_key($exercise_id, $lp_id, $lp_item_id);
        unset($_SESSION['expired_time'][$current_expired_time_key]);
    }

    /**
      Generates the time control key
     */
    public static function get_time_control_key($exercise_id, $lp_id = 0, $lp_item_id = 0, $course_id = null, $session_id = null)
    {
        $exercise_id = intval($exercise_id);
        $lp_id = intval($lp_id);
        $lp_item_id = intval($lp_item_id);
        if (!$course_id) {
            $course_id = api_get_course_int_id();
        }
        if (!$session_id) {
            $session_id = api_get_session_id();
        }
        return $course_id.'_'.$session_id.'_'.$exercise_id.'_'.api_get_user_id().'_'.$lp_id.'_'.$lp_item_id;
    }

    /**
     * Get session time control
     */
    public static function get_session_time_control_key($exercise_id, $lp_id = 0, $lp_item_id = 0)
    {
        $return_value = 0;
        $time_control_key = self::get_time_control_key($exercise_id, $lp_id, $lp_item_id);
        if (isset($_SESSION['expired_time']) && isset($_SESSION['expired_time'][$time_control_key])) {
            $return_value = $_SESSION['expired_time'][$time_control_key];
        }
        return $return_value;
    }

    /**
     * Gets count of exam results
     * @todo this public static function should be moved in a library  + no global calls
     */
    public static function get_count_exam_results($exercise_id, $extra_where_conditions)
    {
        $count = self::get_exam_results_data(null, null, null, null, $exercise_id, $extra_where_conditions, true);
        return $count;
    }

    /**
     * Gets count of exam results
     * @todo this public static function should be moved in a library  + no global calls
     */
    public static function get_admin_count_exam_results($extra_where_conditions)
    {
        $count = self::get_admin_exam_results_data(null, null, null, null, $extra_where_conditions, true);
        return $count;
    }

    /**
     * Gets the exam'data results
     * @todo this function should be moved in a library  + no global calls
     */
    public static function get_admin_exam_results_data($from, $number_of_items, $column, $direction, $extra_where_conditions = null, $get_count = false)
    {

        if (empty($extra_where_conditions)) {
            $extra_where_conditions = "1 = 1 ";
        }

        $TBL_USER = Database :: get_main_table(TABLE_MAIN_USER);
        $tableCourse = Database :: get_main_table(TABLE_MAIN_COURSE);
        $tableSession = Database :: get_main_table(TABLE_MAIN_SESSION);
        $TBL_EXERCICES = Database :: get_course_table(TABLE_QUIZ_TEST);

        $TBL_TRACK_EXERCICES = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $TBL_TRACK_ATTEMPT_RECORDING = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);

        // sql for chamilo-type tests for teacher / tutor view
        $sql_inner_join_tbl_track_exercices = " (
            SELECT DISTINCT ttte.*
            FROM $TBL_TRACK_EXERCICES ttte LEFT JOIN $TBL_TRACK_ATTEMPT_RECORDING tr
            ON (ttte.exe_id = tr.exe_id)
        )";

        $first_and_last_name = api_is_western_name_order() ? "firstname, lastname" : "lastname, firstname";

        if ($get_count) {
            $sql_select = "SELECT count(te.exe_id) ";
        } else {
            $sql_select = "SELECT DISTINCT
                    user_id,
                    $first_and_last_name,
                    ce.title,
                    username,
                    session.name as session,
                    te.exe_result,
                    te.exe_weighting,
                    te.exe_date,
                    te.exe_id,
                    email as exemail,
                    te.start_date,
                    steps_counter,
                    exe_user_id,
                    te.exe_duration,
                    propagate_neg,
                    te.c_id,
                    te.session_id,
                    course.code,
                    orig_lp_id";
        }

        $sql = " $sql_select
                FROM $TBL_EXERCICES AS ce
                INNER JOIN $sql_inner_join_tbl_track_exercices AS te ON (te.exe_exo_id = ce.iid)
                INNER JOIN $TBL_USER  AS user ON (user.user_id = exe_user_id)
                INNER JOIN $tableCourse AS course ON (course.id = te.c_id)
                INNER JOIN $tableSession AS session ON (session.id = te.session_id)

                WHERE $extra_where_conditions AND
                    te.status != 'incomplete' AND
                    ce.active <>-1
                ";

        $column = !empty($column) ? Database::escape_string($column) : null;
        $from = intval($from);
        $number_of_items = intval($number_of_items);

        // just count how many answers
        if ($get_count) {
            $res = Database::query($sql);
            return Database::num_rows($res);
        }

        if (!empty($column)) {
            $sql .= " ORDER BY $column $direction ";
        }
        if ($get_count == false) {
            $sql .= " LIMIT $from, $number_of_items";
        }

        $results = array();
        $resx = Database::query($sql);
        while ($rowx = Database::fetch_array($resx, 'ASSOC')) {
            $results[] = $rowx;
        }

        $list_info = array();

        if (is_array($results)) {
            // Looping results.
            foreach ($results as $result) {

                $id = $result['exe_id'];
                $my_res = $result['exe_result'];
                $my_total = $result['exe_weighting'];

                if (!$result['propagate_neg'] && $my_res < 0) {
                    $my_res = 0;
                }

                $score = self::show_score($my_res, $my_total);

                $courseLink = 'cidReq='.$result['code'].'&id_session='.$result['session_id'];

                $url = api_get_path(WEB_CODE_PATH).'exercice/exercise_show.php?'.$courseLink.'&action=edit&id='.$id;
                $link = Display::url('exercise', $url);
                $result['link'] = $link;
                $result['score'] = $score;

                $list_info[] = $result;
            }
        }

        return $list_info;
    }

    public static function get_count_exam_hotpotatoes_results($in_hotpot_path)
    {
        return self::get_exam_results_hotpotatoes_data(0, 0, '', '', $in_hotpot_path, true, '');
    }

    //function get_exam_results_hotpotatoes_data($from, $number_of_items, $column, $direction, $exercise_id, $extra_where_conditions = null, $get_count = false) {
    public static function get_exam_results_hotpotatoes_data($in_from, $in_number_of_items, $in_column, $in_direction, $in_hotpot_path, $in_get_count = false, $where_condition = null)
    {
        $tab_res = array();
        $courseId = api_get_course_int_id();

        // by default in_column = 1 If parameters given, it is the name of the column witch is the bdd field name
        if ($in_column == 1) {
            $in_column = 'firstname';
        }

        $TBL_TRACK_HOTPOTATOES = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_HOTPOTATOES);
        $TBL_USER = Database :: get_main_table(TABLE_MAIN_USER);

        $sql = "SELECT * FROM $TBL_TRACK_HOTPOTATOES thp
                JOIN $TBL_USER u ON thp.exe_user_id = u.user_id
                WHERE thp.c_id = '$courseId' AND
                      exe_name LIKE '$in_hotpot_path%'";

        // just count how many answers
        if ($in_get_count) {
            $res = Database::query($sql);
            return Database::num_rows($res);
        }

        // get a number of sorted results
        $sql .= " $where_condition ORDER BY $in_column $in_direction  LIMIT $in_from, $in_number_of_items";

        $res = Database::query($sql);
        while ($data = Database::fetch_array($res)) {
            $tab_one_res = array();
            $tab_one_res['firstname'] = $data['firstname'];
            $tab_one_res['lastname'] = $data['lastname'];
            $tab_one_res['username'] = $data['username'];
            $tab_one_res['group_name'] = implode("<br/>", GroupManager::get_user_group_name($data['user_id']));
            $tab_one_res['exe_date'] = $data['exe_date'];
            $tab_one_res['score'] = $data['exe_result'].'/'.$data['exe_weighting'];
            $tab_one_res['actions'] = "";
            $tab_res[] = $tab_one_res;
        }
        return $tab_res;
    }

    /**
     * Gets the exam'data results
     * @todo this function should be moved in a library  + no global calls
     */
    public static function get_exam_results_data($from, $number_of_items, $column, $direction, $exercise_id, $extra_where_conditions = null, $get_count = false)
    {
        //@todo replace all this globals
        global $documentPath, $filter;

        if (empty($extra_where_conditions)) {
            $extra_where_conditions = "1 = 1 ";
        }

        $course_id = api_get_course_int_id();
        $is_allowedToEdit = api_is_allowed_to_edit(null, true) || api_is_allowed_to_edit(true) || api_is_drh();

        $TBL_USER = Database :: get_main_table(TABLE_MAIN_USER);
        $TBL_EXERCICES = Database :: get_course_table(TABLE_QUIZ_TEST);
        $TBL_GROUP_REL_USER = Database :: get_course_table(TABLE_GROUP_USER);
        $TBL_GROUP = Database :: get_course_table(TABLE_GROUP);

        $TBL_TRACK_EXERCICES = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $TBL_TRACK_HOTPOTATOES = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_HOTPOTATOES);
        $TBL_TRACK_ATTEMPT_RECORDING = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
        $session_id_and = ' AND te.session_id = '.api_get_session_id().' ';

        $exercise_id = intval($exercise_id);

        $exercise_where = '';
        if (!empty($exercise_id)) {
            $exercise_where .= ' AND te.exe_exo_id = '.$exercise_id.'  ';
        }

        $hotpotatoe_where = '';
        if (!empty($_GET['path'])) {
            $hotpotatoe_path = Database::escape_string($_GET['path']);
            $hotpotatoe_where .= ' AND exe_name = "'.$hotpotatoe_path.'"  ';
        }

        // sql for chamilo-type tests for teacher / tutor view
        $sql_inner_join_tbl_track_exercices = " (
            SELECT DISTINCT ttte.*, if(tr.exe_id,1, 0) as revised
            FROM $TBL_TRACK_EXERCICES ttte LEFT JOIN $TBL_TRACK_ATTEMPT_RECORDING tr
            ON (ttte.exe_id = tr.exe_id)
            WHERE ttte.c_id = '$course_id' AND
                  exe_exo_id = $exercise_id AND
                  ttte.session_id = ".api_get_session_id()."
        )";
        if ($is_allowedToEdit) {
            //Teacher view
            if (isset($_GET['gradebook']) && $_GET['gradebook'] == 'view') {
                //$exercise_where_query = ' te.exe_exo_id = ce.id AND ';
            }

            $sqlFromOption = "";
            $sqlWhereOption = "";
            //@todo fix to work with COURSE_RELATION_TYPE_RRHH in both queries
            //Hack in order to filter groups
            $sql_inner_join_tbl_user = '';

            if (strpos($extra_where_conditions, 'group_id')) {
                $sql_inner_join_tbl_user = "
                (
                    SELECT u.user_id, firstname, lastname, email, username, g.name as group_name, g.id as group_id
                    FROM $TBL_USER u
                    INNER JOIN $TBL_GROUP_REL_USER gru ON ( gru.user_id = u.user_id AND gru.c_id=".$course_id.")
                    INNER JOIN $TBL_GROUP g ON (gru.group_id = g.id AND g.c_id=".$course_id.")
                )";
            }

            if (strpos($extra_where_conditions, 'group_all')) {

                $extra_where_conditions = str_replace("AND (  group_id = 'group_all'  )", '', $extra_where_conditions);
                $extra_where_conditions = str_replace("AND group_id = 'group_all'", '', $extra_where_conditions);
                $extra_where_conditions = str_replace("group_id = 'group_all' AND", '', $extra_where_conditions);

                $sql_inner_join_tbl_user = "
                (
                    SELECT u.user_id, firstname, lastname, email, username, '' as group_name, '' as group_id
                    FROM $TBL_USER u
                )";
                $sql_inner_join_tbl_user = null;
            }

            if (strpos($extra_where_conditions, 'group_none')) {
                $extra_where_conditions = str_replace("AND (  group_id = 'group_none'  )", "AND (  group_id is null  )", $extra_where_conditions);
                $extra_where_conditions = str_replace("AND group_id = 'group_none'", "AND (  group_id is null  )", $extra_where_conditions);
                $sql_inner_join_tbl_user = "
                (
                    SELECT u.user_id, firstname, lastname, email, username, g.name as group_name, g.id as group_id
                    FROM $TBL_USER u
                    LEFT OUTER JOIN $TBL_GROUP_REL_USER gru ON ( gru.user_id = u.user_id AND gru.c_id=".$course_id." )
                    LEFT OUTER JOIN $TBL_GROUP g ON (gru.group_id = g.id AND g.c_id = ".$course_id.")
                )";
            }

            //All
            $is_empty_sql_inner_join_tbl_user = false;

            if (empty($sql_inner_join_tbl_user)) {
                $is_empty_sql_inner_join_tbl_user = true;
                $sql_inner_join_tbl_user = "
                (
                    SELECT u.user_id, firstname, lastname, email, username, ' ' as group_name, '' as group_id
                    FROM $TBL_USER u
                )";
            }


            $sqlFromOption = " , $TBL_GROUP_REL_USER AS gru ";
            $sqlWhereOption = "  AND gru.c_id = ".api_get_course_int_id()." AND gru.user_id = user.user_id ";

            $first_and_last_name = api_is_western_name_order() ? "firstname, lastname" : "lastname, firstname";

            if ($get_count) {
                $sql_select = "SELECT count(te.exe_id) ";
            } else {
                $sql_select = "SELECT DISTINCT
                        user_id,
                        $first_and_last_name,
                        ce.title,
                        username,
                        te.exe_result,
                        te.exe_weighting,
                        te.exe_date,
                        te.exe_id,
                        email as exemail,
                        te.start_date,
                        steps_counter,
                        exe_user_id,
                        te.exe_duration,
                        propagate_neg,
                        revised,
                        group_name,
                        group_id,
                        orig_lp_id";
            }

            $sql = " $sql_select
                    FROM $TBL_EXERCICES AS ce
                    INNER JOIN $sql_inner_join_tbl_track_exercices AS te ON (te.exe_exo_id = ce.iid)
                    INNER JOIN $sql_inner_join_tbl_user  AS user ON (user.user_id = exe_user_id)
                    WHERE $extra_where_conditions AND
                        te.status != 'incomplete'
                        AND te.c_id='".$course_id."' $session_id_and
                        AND ce.active <>-1
                        AND ce.c_id=".$course_id."
                        $exercise_where ";

            // sql for hotpotatoes tests for teacher / tutor view

            if ($get_count) {
                $hpsql_select = "SELECT count(username)";
            } else {
                $hpsql_select = "SELECT
                        $first_and_last_name ,
                        username,
                        tth.exe_name,
                        tth.exe_result ,
                        tth.exe_weighting,
                        tth.exe_date";
            }
            //	AND $where_condition seems not to be used
            $hpsql = " $hpsql_select
                    FROM
                        $TBL_TRACK_HOTPOTATOES tth,
                        $TBL_USER user
                        $sqlFromOption
                    WHERE
                        user.user_id=tth.exe_user_id
                        AND tth.c_id = '".$course_id."'
                        $hotpotatoe_where
                        $sqlWhereOption

                    ORDER BY
                        tth.c_id ASC,
                        tth.exe_date DESC";
        }

        if ($get_count) {
            $resx = Database::query($sql);
            $rowx = Database::fetch_row($resx, 'ASSOC');
            return $rowx[0];
        }

        $teacher_list = CourseManager::get_teacher_list_from_course_code(api_get_course_int_id());
        $teacher_id_list = array();
        foreach ($teacher_list as $teacher) {
            $teacher_id_list[] = $teacher['user_id'];
        }

        // Simple exercises.
        if (empty($hotpotatoe_where)) {
            $column = !empty($column) ? Database::escape_string($column) : null;
            $from = intval($from);
            $number_of_items = intval($number_of_items);

            if (!empty($column)) {
                $sql .= " ORDER BY $column $direction ";
            }
            $sql .= " LIMIT $from, $number_of_items";

            $results = array();

            $resx = Database::query($sql);
            while ($rowx = Database::fetch_array($resx, 'ASSOC')) {
                $results[] = $rowx;
            }

            $list_info = array();

            $group_list = GroupManager::get_group_list();
            $clean_group_list = array();

            if (!empty($group_list)) {
                foreach ($group_list as $group) {
                    $clean_group_list[$group['id']] = $group['name'];
                }
            }

            $lp_list_obj = new LearnpathList(api_get_user_id());
            $lp_list = $lp_list_obj->get_flat_list();

            if (is_array($results)) {

                $users_array_id = array();
                if (isset($_GET['gradebook']) && $_GET['gradebook'] == 'view') {
                    $from_gradebook = true;
                }
                $sizeof = count($results);

                $user_list_id = array();

                $locked = api_resource_is_locked_by_gradebook($exercise_id, LINK_EXERCISE);

                //Looping results
                for ($i = 0; $i < $sizeof; $i++) {
                    $revised = $results[$i]['revised'];

                    if (isset($from_gradebook) && $from_gradebook && $is_allowedToEdit) {
                        if (in_array($results[$i]['username'].$results[$i]['firstname'].$results[$i]['lastname'], $users_array_id)) {
                            continue;
                        }
                        $users_array_id[] = $results[$i]['username'].$results[$i]['firstname'].$results[$i]['lastname'];
                    }

                    $lp_obj = isset($results[$i]['orig_lp_id']) && isset($lp_list[$results[$i]['orig_lp_id']]) ? $lp_list[$results[$i]['orig_lp_id']] : null;
                    $lp_name = null;

                    if ($lp_obj) {
                        $url = api_get_path(WEB_CODE_PATH).'newscorm/lp_controller.php?'.api_get_cidreq().'&action=view&lp_id='.$results[$i]['orig_lp_id'];
                        $lp_name = Display::url($lp_obj['lp_name'], $url, array('target' => '_blank'));
                    }

                    //Add all groups by user
                    $group_name_list = null;

                    if ($is_empty_sql_inner_join_tbl_user) {
                        $group_list = GroupManager::get_group_ids(api_get_course_int_id(), $results[$i]['user_id']);

                        foreach ($group_list as $id) {
                            $group_name_list .= $clean_group_list[$id].'<br/>';
                        }
                        $results[$i]['group_name'] = $group_name_list;
                    }

                    $results[$i]['exe_duration'] = !empty($results[$i]['exe_duration']) ? round($results[$i]['exe_duration'] / 60) : 0;

                    $user_list_id[] = $results[$i]['exe_user_id'];
                    $id = $results[$i]['exe_id'];

                    $dt = api_convert_and_format_date($results[$i]['exe_weighting']);

                    // we filter the results if we have the permission to
                    if (isset($results[$i]['results_disabled'])) {
                        $result_disabled = intval($results[$i]['results_disabled']);
                    } else {
                        $result_disabled = 0;
                    }

                    if ($result_disabled == 0) {

                        $my_res = $results[$i]['exe_result'];
                        $my_total = $results[$i]['exe_weighting'];

                        $results[$i]['start_date'] = api_get_local_time($results[$i]['start_date']);
                        $results[$i]['exe_date'] = api_get_local_time($results[$i]['exe_date']);

                        if (!$results[$i]['propagate_neg'] && $my_res < 0) {
                            $my_res = 0;
                        }
                        $score = self::show_score($my_res, $my_total);

                        $actions = '';
                        if ($is_allowedToEdit) {
                            if (isset($teacher_id_list)) {
                                if (in_array($results[$i]['exe_user_id'], $teacher_id_list)) {
                                    $actions .= Display::return_icon('teachers.gif', get_lang('Teacher'));
                                }
                            }
                            if ($revised) {
                                $actions .= "<a href='exercise_show.php?".api_get_cidreq()."&action=edit&id=$id'>".Display :: return_icon('edit.png', get_lang('Edit'), array(), ICON_SIZE_SMALL);
                                $actions .= '&nbsp;';
                            } else {
                                $actions .="<a href='exercise_show.php?".api_get_cidreq()."&action=qualify&id=$id'>".Display :: return_icon('quiz.gif', get_lang('Qualify'));
                                $actions .='&nbsp;';
                            }
                            $actions .="</a>";

                            if ($filter == 2) {
                                $actions .=' <a href="exercise_history.php?'.api_get_cidreq().'&exe_id='.$id.'">'.Display :: return_icon('history.gif', get_lang('ViewHistoryChange')).'</a>';
                            }

                            //Admin can always delete the attempt
                            if ($locked == false || api_is_platform_admin()) {
                                $ip = TrackingUserLog::get_ip_from_user_event($results[$i]['exe_user_id'], $results[$i]['exe_date'], false);
                                $actions .= '<a href="http://www.whatsmyip.org/ip-geo-location/?ip='.$ip.'" target="_blank"><img src="'.api_get_path(WEB_CODE_PATH).'img/icons/22/info.png" title="'.$ip.'" /></a>';
                                $delete_link = '<a href="exercise_report.php?'.api_get_cidreq().'&filter_by_user='.intval($_GET['filter_by_user']).'&filter=' . $filter . '&exerciseId='.$exercise_id.'&delete=delete&did=' . $id . '"
                                    onclick="javascript:if(!confirm(\'' . sprintf(get_lang('DeleteAttempt'), $results[$i]['username'], $dt) . '\')) return false;">'.Display :: return_icon('delete.png', get_lang('Delete')).'</a>';
                                $delete_link = utf8_encode($delete_link);
                                $actions .= $delete_link.'&nbsp;';
                            }
                        } else {
                            $attempt_url = api_get_path(WEB_CODE_PATH).'exercice/result.php?'.api_get_cidreq().'&id='.$results[$i]['exe_id'].'&id_session='.api_get_session_id().'&height=500&width=750';
                            $attempt_link = Display::url(get_lang('Show'), $attempt_url, array('class' => 'ajax btn'));
                            $actions .= $attempt_link;
                        }

                        if ($revised) {
                            $revised = Display::label(get_lang('Validated'), 'success');
                        } else {
                            $revised = Display::label(get_lang('NotValidated'), 'info');
                        }

                        if ($is_allowedToEdit) {
                            $results[$i]['status'] = $revised;
                            $results[$i]['score'] = $score;
                            $results[$i]['lp'] = $lp_name;
                            $results[$i]['actions'] = $actions;
                            $list_info[] = $results[$i];
                        } else {
                            $results[$i]['status'] = $revised;
                            $results[$i]['score'] = $score;
                            $results[$i]['actions'] = $actions;
                            $list_info[] = $results[$i];
                        }
                    }
                }
            }
        } else {

            $hpresults = getManyResultsXCol($hpsql, 6);

            // Print HotPotatoes test results.
            if (is_array($hpresults)) {

                for ($i = 0; $i < sizeof($hpresults); $i++) {
                    $hp_title = GetQuizName($hpresults[$i][3], $documentPath);
                    if ($hp_title == '') {
                        $hp_title = basename($hpresults[$i][3]);
                    }

                    $hp_date = api_get_local_time($hpresults[$i][6], null, date_default_timezone_get());
                    $hp_result = round(($hpresults[$i][4] / ($hpresults[$i][5] != 0 ? $hpresults[$i][5] : 1)) * 100, 2).'% ('.$hpresults[$i][4].' / '.$hpresults[$i][5].')';
                    if ($is_allowedToEdit) {
                        $list_info[] = array($hpresults[$i][0], $hpresults[$i][1], $hpresults[$i][2], '', $hp_title, '-', $hp_date, $hp_result, '-');
                    } else {
                        $list_info[] = array($hp_title, '-', $hp_date, $hp_result, '-');
                    }
                }
            }
        }

        return $list_info;
    }

    /**
     * Converts the score with the exercise_max_note and exercise_min_score the platform settings + formats the results using the Text::float_format function
     *
     * @param   float   score
     * @param   float   weight
     * @param   bool    show porcentage or not
     * @param	 bool	use or not the platform settings
     * @return  string  an html with the score modified
     */
    public static function show_score($score, $weight, $show_percentage = true, $use_platform_settings = true, $show_only_percentage = false)
    {
        if (is_null($score) && is_null($weight)) {
            return '-';
        }

        $max_note = api_get_setting('exercise_max_score');
        $min_note = api_get_setting('exercise_min_score');

        if ($use_platform_settings) {
            if ($max_note != '' && $min_note != '') {
                if (!empty($weight) && intval($weight) != 0) {
                    $score = $min_note + ($max_note - $min_note) * $score / $weight;
                } else {
                    $score = $min_note;
                }
                $weight = $max_note;
            }
        }
        $percentage = (100 * $score) / ($weight != 0 ? $weight : 1);

        //Formats values
        $percentage = Text::float_format($percentage, 1);
        $score = Text::float_format($score, 1);
        $weight = Text::float_format($weight, 1);

        $html = null;
        if ($show_percentage) {
            $parent = '('.$score.' / '.$weight.')';
            $html = $percentage." %  $parent";
            if ($show_only_percentage) {
                $html = $percentage."% ";
            }
        } else {
            $html = $score.' / '.$weight;
        }
        $html = Display::span($html, array('class' => 'score_exercise'));
        return $html;
    }

    public static function is_success_exercise_result($score, $weight, $pass_percentage)
    {
        $percentage = Text::float_format(($score / ($weight != 0 ? $weight : 1)) * 100, 1);
        if (isset($pass_percentage) && !empty($pass_percentage)) {
            if ($percentage >= $pass_percentage) {
                return true;
            }
        }
        return false;
    }

    public static function show_success_message($score, $weight, $pass_percentage)
    {
        $res = "";
        if (self::is_pass_pourcentage_enabled($pass_percentage)) {
            $is_success = self::is_success_exercise_result($score, $weight, $pass_percentage);

            $icon = '';
            if ($is_success) {
                $html = get_lang('CongratulationsYouPassedTheTest');
                $icon = Display::return_icon('completed.png', get_lang('Correct'), array(), ICON_SIZE_MEDIUM);
            } else {
                //$html .= Display::return_message(get_lang('YouDidNotReachTheMinimumScore'), 'warning');
                $html = get_lang('YouDidNotReachTheMinimumScore');
                $icon = Display::return_icon('warning.png', get_lang('Wrong'), array(), ICON_SIZE_MEDIUM);
            }
            $html = Display::tag('h4', $html);
            $html .= Display::tag('h5', $icon, array('style' => 'width:40px; padding:2px 10px 0px 0px'));
            $res = $html;
        }
        return $res;
    }

    /**
     * Return true if pass_pourcentage activated (we use the pass pourcentage feature
     * return false if pass_percentage = 0 (we don't use the pass pourcentage feature
     * @param $in_pass_pourcentage
     * @return boolean
     * In this version, pass_percentage and show_success_message are disabled if
     * pass_percentage is set to 0
     */
    public static function is_pass_pourcentage_enabled($in_pass_pourcentage)
    {
        return $in_pass_pourcentage > 0;
    }

    /**
     * Converts a numeric value in a percentage example 0.66666 to 66.67 %
     * @param $value
     * @return float Converted number
     */
    public static function convert_to_percentage($value)
    {
        $return = '-';
        if ($value != '') {
            $return = Text::float_format($value * 100, 1).' %';
        }
        return $return;
    }

    /**
     * Converts a score/weight values to the platform scale
     * @param   float   score
     * @param   float   weight
     * @return  float   the score rounded converted to the new range
     */
    public static function convert_score($score, $weight)
    {
        $max_note = api_get_setting('exercise_max_score');
        $min_note = api_get_setting('exercise_min_score');

        if ($score != '' && $weight != '') {
            if ($max_note != '' && $min_note != '') {
                if (!empty($weight)) {
                    $score = $min_note + ($max_note - $min_note) * $score / $weight;
                } else {
                    $score = $min_note;
                }
            }
        }
        $score_rounded = Text::float_format($score, 1);
        return $score_rounded;
    }

    /**
     * Getting all active exercises from a course from a session (if a session_id is provided we will show all the exercises in the course + all exercises in the session)
     * @param   array   course data
     * @param   int     session id
     * @return  array   array with exercise data
     */
    public static function get_all_exercises($course_info = null, $session_id = 0, $check_publication_dates = false)
    {
        $TBL_EXERCICES = Database :: get_course_table(TABLE_QUIZ_TEST);
        $course_id = api_get_course_int_id();
        if (!empty($course_info) && !empty($course_info['real_id'])) {
            $course_id = $course_info['real_id'];
        }

        if ($session_id == -1) {
            $session_id = 0;
        }

        $now = api_get_utc_datetime();
        $time_conditions = '';

        if ($check_publication_dates) {
            $time_conditions = " AND ((start_time <> '0000-00-00 00:00:00' AND start_time < '$now'  AND end_time <> '0000-00-00 00:00:00' AND end_time > '$now' ) OR "; //start and end are set
            $time_conditions .= " (start_time <> '0000-00-00 00:00:00' AND start_time < '$now'  AND end_time = '0000-00-00 00:00:00') OR "; // only start is set
            $time_conditions .= " (start_time = '0000-00-00 00:00:00'   AND end_time <> '0000-00-00 00:00:00'  AND end_time > '$now') OR   "; // only end is set
            $time_conditions .= " (start_time = '0000-00-00 00:00:00'   AND end_time =  '0000-00-00 00:00:00'))  "; // nothing is set
        }

        if ($session_id == 0) {
            $conditions = array('where' => array('active = ? AND session_id = ? AND c_id = ? '.$time_conditions => array('1', $session_id, $course_id)), 'order' => 'title');
        } else {
            //All exercises
            $conditions = array('where' => array('active = ? AND  (session_id = 0 OR session_id = ? ) AND c_id = ? '.$time_conditions => array('1', $session_id, $course_id)), 'order' => 'title');
        }
        $result = Database::select('*', $TBL_EXERCICES, $conditions);
        return $result;
    }

    /**
     * Getting all active exercises from a course from a session (if a session_id is provided we will show all the exercises in the course + all exercises in the session)
     * @param   int session id
     * @param   int course c_id
     * @return  array   array with exercise data
     * modified by Hubert Borderiou
     */
    public static function get_all_exercises_for_course_id($session_id = 0, $course_id = 0)
    {
        $TBL_EXERCICES = Database :: get_course_table(TABLE_QUIZ_TEST);
        if ($session_id == -1) {
            $session_id = 0;
        }
        if ($session_id == 0) {
            $conditions = array('where' => array('active = ? AND session_id = ? AND c_id = ?' => array('1', $session_id, $course_id)), 'order' => 'title');
        } else {
            //All exercises
            $conditions = array('where' => array('active = ? AND (session_id = 0 OR session_id = ? ) AND c_id=?' => array('1', $session_id, $course_id)), 'order' => 'title');
        }
        return Database::select('*', $TBL_EXERCICES, $conditions);
    }

    /**
     * Gets the position of the score based in a given score (result/weight) and the exe_id based in the user list
     * (NO Exercises in LPs )
     * @param   float   user score to be compared *attention* $my_score = score/weight and not just the score
     * @param   int     exe id of the exercise (this is necesary because if 2 students have the same score the one with the minor exe_id will have a best position, just to be fair and FIFO)
     * @param   int     exercise id
     * @param   string  course code
     * @param   int     session id
     * @return  int     the position of the user between his friends in a course (or course within a session)
     */
    public static function get_exercise_result_ranking($my_score, $my_exe_id, $exercise_id, $course_id, $session_id = 0, $user_list = array(), $return_string = true)
    {
        //No score given we return
        if (is_null($my_score)) {
            return '-';
        }
        if (empty($user_list)) {
            return '-';
        }

        $best_attempts = array();
        foreach ($user_list as $user_data) {
            $user_id = $user_data['user_id'];
            $best_attempts[$user_id] = self::get_best_attempt_by_user($user_id, $exercise_id, $course_id, $session_id);
        }

        if (empty($best_attempts)) {
            return 1;
        } else {
            $position = 1;
            $my_ranking = array();
            foreach ($best_attempts as $user_id => $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $my_ranking[$user_id] = $result['exe_result'] / $result['exe_weighting'];
                } else {
                    $my_ranking[$user_id] = 0;
                }
            }
            //if (!empty($my_ranking)) {
            asort($my_ranking);
            $position = count($my_ranking);
            if (!empty($my_ranking)) {
                foreach ($my_ranking as $user_id => $ranking) {
                    if ($my_score >= $ranking) {
                        if ($my_score == $ranking) {
                            $exe_id = $best_attempts[$user_id]['exe_id'];
                            if ($my_exe_id < $exe_id) {
                                $position--;
                            }
                        } else {
                            $position--;
                        }
                    }
                }
            }
            //}
            $return_value = array('position' => $position, 'count' => count($my_ranking));

            if ($return_string) {
                if (!empty($position) && !empty($my_ranking)) {
                    $return_value = $position.'/'.count($my_ranking);
                } else {
                    $return_value = '-';
                }
            }
            return $return_value;
        }
    }

    /**
     * Gets the position of the score based in a given score (result/weight) and the exe_id based in all attempts
     * (NO Exercises in LPs ) old funcionality by attempt
     * @param   float   user score to be compared attention => score/weight
     * @param   int     exe id of the exercise (this is necesary because if 2 students have the same score the one with the minor exe_id will have a best position, just to be fair and FIFO)
     * @param   int     exercise id
     * @param   int     course id
     * @param   int     session id
     * @todo seems that is not used
     * @return  int     the position of the user between his friends in a course (or course within a session)
     */
    public static function get_exercise_result_ranking_by_attempt($my_score, $my_exe_id, $exercise_id, $courseId, $session_id = 0, $return_string = true)
    {
        if (empty($session_id)) {
            $session_id = 0;
        }
        if (is_null($my_score)) {
            return '-';
        }
        $user_results = self::get_all_exercise_results($exercise_id, $courseId, $session_id, false);
        $position_data = array();
        if (empty($user_results)) {
            return 1;
        } else {
            $position = 1;
            $my_ranking = array();
            foreach ($user_results as $result) {
                //print_r($result);
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $my_ranking[$result['exe_id']] = $result['exe_result'] / $result['exe_weighting'];
                } else {
                    $my_ranking[$result['exe_id']] = 0;
                }
            }
            asort($my_ranking);
            $position = count($my_ranking);
            if (!empty($my_ranking)) {
                foreach ($my_ranking as $exe_id => $ranking) {
                    if ($my_score >= $ranking) {
                        if ($my_score == $ranking) {
                            if ($my_exe_id < $exe_id) {
                                $position--;
                            }
                        } else {
                            $position--;
                        }
                    }
                }
            }
            $return_value = array('position' => $position, 'count' => count($my_ranking));

            if ($return_string) {
                if (!empty($position) && !empty($my_ranking)) {
                    return $position.'/'.count($my_ranking);
                }
            }
            return $return_value;
        }
    }
    /*
     *  Get the best attempt in a exercise (NO Exercises in LPs )
     */

    public static function get_best_attempt_in_course($exercise_id, $courseId, $session_id)
    {
        $user_results = self::get_all_exercise_results($exercise_id, $courseId, $session_id, false);
        $best_score_data = array();
        $best_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    if ($score >= $best_score) {
                        $best_score = $score;
                        $best_score_data = $result;
                    }
                }
            }
        }
        return $best_score_data;
    }

    /**
     * Get the best score in a exercise (NO Exercises in LPs )
     * @param $user_id
     * @param $exercise_id
     * @param $courseId
     * @param $session_id
     * @return array
     */
    public static function get_best_attempt_by_user($user_id, $exercise_id, $courseId, $session_id)
    {
        $user_results = self::get_all_exercise_results($exercise_id, $courseId, $session_id, false, $user_id);
        $best_score_data = array();
        $best_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    if ($score >= $best_score) {
                        $best_score = $score;
                        $best_score_data = $result;
                    }
                }
            }
        }
        return $best_score_data;
    }

    /**
     * Get average score (NO Exercises in LPs )
     * @param 	int	exercise id
     * @param 	int	course id
     * @param 	int	session id
     * @return 	float	Average score
     */
    public static function get_average_score($exercise_id, $courseId, $session_id)
    {
        $user_results = self::get_all_exercise_results($exercise_id, $courseId, $session_id);
        $avg_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    $avg_score +=$score;
                }
            }
            $avg_score = Text::float_format($avg_score / count($user_results), 1);
        }
        return $avg_score;
    }

    /**
     * Get average score by score (NO Exercises in LPs )
     * @param 	int	exercise id
     * @param 	int	course id
     * @param 	int	session id
     * @return 	float	Average score
     */
    public static function get_average_score_by_course($courseId, $session_id)
    {
        $user_results = self::get_all_exercise_results_by_course($courseId, $session_id, false);
        $avg_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    $avg_score +=$score;
                }
            }
            //We asume that all exe_weighting
            //$avg_score = show_score( $avg_score / count($user_results) , $result['exe_weighting']);
            $avg_score = ($avg_score / count($user_results));
        }
        return $avg_score;
    }

    /**
     *
     * @param $user_id
     * @param $courseId
     * @param $session_id
     *
     * @return float|int
     */
    public static function get_average_score_by_course_by_user($user_id, $courseId, $session_id)
    {
        $user_results = self::get_all_exercise_results_by_user($user_id, $courseId, $session_id);
        $avg_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    $avg_score +=$score;
                }
            }
            //We asume that all exe_weighting
            //$avg_score = show_score( $avg_score / count($user_results) , $result['exe_weighting']);
            $avg_score = ($avg_score / count($user_results));
        }
        return $avg_score;
    }

    /**
     * Get average score by score (NO Exercises in LPs )
     * @param 	int		exercise id
     * @param 	int course id
     * @param 	int		session id
     *
     * @return	float	Best average score
     */
    public static function get_best_average_score_by_exercise($exercise_id, $course_code, $session_id, $user_count)
    {
        $user_results = self::get_best_exercise_results_by_user($exercise_id, $course_code, $session_id);
        $avg_score = 0;
        if (!empty($user_results)) {
            foreach ($user_results as $result) {
                if (!empty($result['exe_weighting']) && intval($result['exe_weighting']) != 0) {
                    $score = $result['exe_result'] / $result['exe_weighting'];
                    $avg_score +=$score;
                }
            }
            //We asume that all exe_weighting
            //$avg_score = show_score( $avg_score / count($user_results) , $result['exe_weighting']);
            //$avg_score = ($avg_score / count($user_results));
            if (!empty($user_count)) {
                $avg_score = Text::float_format($avg_score / $user_count, 1) * 100;
            } else {
                $avg_score = 0;
            }
        }
        return $avg_score;
    }

    /**
     * @param $course_code
     * @param $session_id
     * @return array
     */
    public static function get_exercises_to_be_taken($course_code, $session_id)
    {
        $course_info = api_get_course_info($course_code);
        $exercises = self::get_all_exercises($course_info, $session_id);
        $result = array();
        $now = time() + 15 * 24 * 60 * 60;
        foreach ($exercises as $exercise_item) {
            if (isset($exercise_item['end_time']) && !empty($exercise_item['end_time']) && $exercise_item['end_time'] != '0000-00-00 00:00:00' && api_strtotime($exercise_item['end_time'], 'UTC') < $now) {
                $result[] = $exercise_item;
            }
        }
        return $result;
    }

    /**
     * Get student results (only in completed exercises) stats by question
     *
     * @param 	int		question id
     * @param 	int		exercise id
     * @param 	int 	course id
     * @param 	int		session id
     *
     * */
    public static function get_student_stats_by_question($question_id, $exercise_id, $courseId, $session_id)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $question_id = intval($question_id);
        $exercise_id = intval($exercise_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT MAX(marks) as max , MIN(marks) as min, AVG(marks) as average
                FROM $track_exercises e INNER JOIN $track_attempt a ON (a.exe_id = e.exe_id)
                WHERE 	exe_exo_id 		= $exercise_id AND
                        e.c_id 	= $courseId AND
                        a.c_id = $courseId AND
                        e.session_id 	= $session_id AND
                        question_id 	= $question_id AND
                        status = ''
                LIMIT 1";
        $result = Database::query($sql);
        $return = array();
        if ($result) {
            $return = Database::fetch_array($result, 'ASSOC');
        }
        return $return;
    }

    /**
     * @param int $question_id
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @return int
     */
    public static function get_number_students_question_with_answer_count($question_id, $exercise_id, $courseId, $session_id)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $question_id = intval($question_id);
        $exercise_id = intval($exercise_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT DISTINCT exe_user_id
                FROM $track_exercises e INNER JOIN $track_attempt a ON (a.exe_id = e.exe_id) INNER JOIN $course_user cu
                    ON cu.c_id = a.c_id AND cu.user_id  = exe_user_id
                WHERE 	exe_exo_id 		= $exercise_id AND
                        a.c_id 	        = $courseId AND
                        e.session_id 	= $session_id AND
                        question_id 	= $question_id AND
                        answer          <> '0' AND
                        cu.status       = ".STUDENT." AND
                        relation_type  <> 2 AND
                        e.status        = ''";
        $result = Database::query($sql);
        $return = 0;
        if ($result) {
            $return = Database::num_rows($result);
        }
        return $return;
    }

    /**
     * @param int $answer_id
     * @param int $question_id
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @return int
     */
    public static function get_number_students_answer_hotspot_count($answer_id, $question_id, $exercise_id, $courseId, $session_id)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_hotspot = Database::get_main_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);
        $course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $question_id = intval($question_id);
        $answer_id = intval($answer_id);
        $exercise_id = intval($exercise_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT DISTINCT exe_user_id
                FROM $track_exercises e
                INNER JOIN $track_hotspot a ON (a.hotspot_exe_id = e.exe_id)
                INNER JOIN $course_user cu
                    ON cu.c_id = a.c_id AND cu.user_id  = exe_user_id
                WHERE 	exe_exo_id              = $exercise_id AND
                        a.c_id               	= $courseId AND
                        e.session_id            = $session_id AND
                        hotspot_answer_id       = $answer_id AND
                        hotspot_question_id     = $question_id AND
                        cu.status               = ".STUDENT." AND
                        hotspot_correct         =  1 AND
                        relation_type           <> 2 AND
                        e.status                = ''";

        $result = Database::query($sql);
        $return = 0;
        if ($result) {
            $return = Database::num_rows($result);
        }
        return $return;
    }

    /**
     *
     * @param int $answer_id
     * @param int $question_id
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @param string $question_type
     * @param null $correct_answer
     * @param null $current_answer
     * @return int
     */
    public static function get_number_students_answer_count($answer_id, $question_id, $exercise_id, $courseId, $session_id, $question_type = null, $correct_answer = null, $current_answer = null)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $question_id = intval($question_id);
        $answer_id = intval($answer_id);
        $exercise_id = intval($exercise_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        switch ($question_type) {
            case FILL_IN_BLANKS:
                $answer_condition = "";
                $select_condition = " e.exe_id, answer ";
                break;
            case MATCHING:
            default:
                $answer_condition = " answer = $answer_id AND ";
                $select_condition = " DISTINCT exe_user_id ";
        }

        $sql = "SELECT $select_condition
                FROM $track_exercises e
                    INNER JOIN $track_attempt a ON (a.exe_id = e.exe_id)
                    INNER JOIN $course_user cu
                    ON cu.c_id = a.c_id AND cu.user_id  = exe_user_id
                WHERE 	exe_exo_id 		= $exercise_id AND
                        a.c_id 	= $courseId AND
                        e.session_id 	= $session_id AND
                        $answer_condition
                        question_id 	= $question_id AND
                        cu.status        = ".STUDENT." AND
                        relation_type <> 2 AND
                        e.status = ''";
        $result = Database::query($sql);
        $return = 0;
        if ($result) {
            $good_answers = 0;
            switch ($question_type) {
                case FILL_IN_BLANKS:
                    while ($row = Database::fetch_array($result, 'ASSOC')) {
                        $fill_blank = self::check_fill_in_blanks($correct_answer, $row['answer']);
                        if (isset($fill_blank[$current_answer]) && $fill_blank[$current_answer] == 1) {
                            $good_answers++;
                        }
                    }
                    return $good_answers;
                    break;
                case MATCHING:
                default:
                    $return = Database::num_rows($result);
            }
        }
        return $return;
    }

    public static function check_fill_in_blanks($answer, $user_answer)
    {
        // the question is encoded like this
        // [A] B [C] D [E] F::10,10,10@1
        // number 1 before the "@" means that is a switchable fill in blank question
        // [A] B [C] D [E] F::10,10,10@ or  [A] B [C] D [E] F::10,10,10
        // means that is a normal fill blank question
        // first we explode the "::"
        $pre_array = explode('::', $answer);
        // is switchable fill blank or not
        $last = count($pre_array) - 1;
        $is_set_switchable = explode('@', $pre_array[$last]);
        $switchable_answer_set = false;
        if (isset($is_set_switchable[1]) && $is_set_switchable[1] == 1) {
            $switchable_answer_set = true;
        }
        $answer = '';
        for ($k = 0; $k < $last; $k++) {
            $answer .= $pre_array[$k];
        }
        // splits weightings that are joined with a comma
        $answerWeighting = explode(',', $is_set_switchable[0]);

        // we save the answer because it will be modified
        //$temp = $answer;
        $temp = $answer;

        $answer = '';
        $j = 0;
        //initialise answer tags
        $user_tags = $correct_tags = $real_text = array();
        // the loop will stop at the end of the text
        while (1) {
            // quits the loop if there are no more blanks (detect '[')
            if (($pos = api_strpos($temp, '[')) === false) {
                // adds the end of the text
                $answer = $temp;
                /* // Deprecated code
                  // TeX parsing - replacement of texcode tags
                  $answer = str_replace("{texcode}", $texstring, $answer);
                 */
                $real_text[] = $answer;
                break; //no more "blanks", quit the loop
            }
            // adds the piece of text that is before the blank
            //and ends with '[' into a general storage array
            $real_text[] = api_substr($temp, 0, $pos + 1);
            $answer .= api_substr($temp, 0, $pos + 1);
            //take the string remaining (after the last "[" we found)
            $temp = api_substr($temp, $pos + 1);
            // quit the loop if there are no more blanks, and update $pos to the position of next ']'
            if (($pos = api_strpos($temp, ']')) === false) {
                // adds the end of the text
                $answer .= $temp;
                break;
            }

            $str = $user_answer;

            preg_match_all('#\[([^[]*)\]#', $str, $arr);
            $str = str_replace('\r\n', '', $str);
            $choice = $arr[1];

            $tmp = api_strrpos($choice[$j], ' / ');
            $choice[$j] = api_substr($choice[$j], 0, $tmp);
            $choice[$j] = trim($choice[$j]);

            //Needed to let characters ' and " to work as part of an answer
            $choice[$j] = stripslashes($choice[$j]);

            $user_tags[] = api_strtolower($choice[$j]);
            //put the contents of the [] answer tag into correct_tags[]
            $correct_tags[] = api_strtolower(api_substr($temp, 0, $pos));
            $j++;
            $temp = api_substr($temp, $pos + 1);
        }

        $answer = '';
        $real_correct_tags = $correct_tags;
        $chosen_list = array();

        $good_answer = array();

        for ($i = 0; $i < count($real_correct_tags); $i++) {
            if (!$switchable_answer_set) {
                //needed to parse ' and " characters
                $user_tags[$i] = stripslashes($user_tags[$i]);
                if ($correct_tags[$i] == $user_tags[$i]) {
                    $good_answer[$correct_tags[$i]] = 1;
                } elseif (!empty($user_tags[$i])) {
                    $good_answer[$correct_tags[$i]] = 0;
                } else {
                    $good_answer[$correct_tags[$i]] = 0;
                }
            } else {
                // switchable fill in the blanks
                if (in_array($user_tags[$i], $correct_tags)) {
                    $correct_tags = array_diff($correct_tags, $chosen_list);
                    $good_answer[$correct_tags[$i]] = 1;
                } elseif (!empty($user_tags[$i])) {
                    $good_answer[$correct_tags[$i]] = 0;
                } else {
                    $good_answer[$correct_tags[$i]] = 0;
                }
            }
            // adds the correct word, followed by ] to close the blank
            $answer .= ' / <font color="green"><b>'.$real_correct_tags[$i].'</b></font>]';
            if (isset($real_text[$i + 1])) {
                $answer .= $real_text[$i + 1];
            }
        }
        return $good_answer;
    }

    /**
     *
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @depracated seems not to be used
     * @return int
     */
    public static function get_number_students_finish_exercise($exercise_id, $courseId, $session_id)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $exercise_id = intval($exercise_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT DISTINCT exe_user_id
                FROM $track_exercises e INNER JOIN $track_attempt a ON (a.exe_id = e.exe_id)
                WHERE 	exe_exo_id 		= $exercise_id AND
                        a.c_id = $courseId AND
                        e.c_id = $courseId AND
                        e.session_id 	= $session_id AND
                        status = ''";
        $result = Database::query($sql);
        $return = 0;
        if ($result) {
            $return = Database::num_rows($result);
        }
        return $return;
    }

    /**
       return the HTML code for a menu with students group
       @input : $in_name : is the name and the id of the <select>
                $in_default : default value for option
      @todo deprecated seems not to be used

      @return : the html code of the <select>
     */
    public static function displayGroupMenu($in_name, $in_default, $in_onchange = "")
    {
        // check the default value of option
        $tabSelected = array($in_default => " selected='selected' ");
        $res = "";
        $res .= "<select name='$in_name' id='$in_name' onchange='".$in_onchange."' >";
        $res .= "<option value='-1'".$tabSelected["-1"].">-- ".get_lang('AllGroups')." --</option>";
        $res .= "<option value='0'".$tabSelected["0"].">- ".get_lang('NotInAGroup')." -</option>";
        $tabGroups = GroupManager::get_group_list();
        $currentCatId = 0;
        for ($i = 0; $i < count($tabGroups); $i++) {
            $tabCategory = GroupManager::get_category_from_group($tabGroups[$i]["id"]);
            if ($tabCategory["id"] != $currentCatId) {
                $res .= "<option value='-1' disabled='disabled'>".$tabCategory["title"]."</option>";
                $currentCatId = $tabCategory["id"];
            }
            $res .= "<option ".$tabSelected[$tabGroups[$i]["id"]]."style='margin-left:40px' value='".$tabGroups[$i]["id"]."'>".$tabGroups[$i]["name"]."</option>";
        }
        $res .= "</select>";
        return $res;
    }

    /**
     * Return a list of group for user with user_id=in_userid separated with in_separator
     * @deprecated ?
     */
    public static function displayGroupsForUser($in_separator, $in_userid)
    {
        $res = implode($in_separator, GroupManager::get_user_group_name($in_userid));
        if ($res == "") {
            $res = "<div style='text-align:center'>-</div>";
        }
        return $res;
    }

    public static function create_chat_exercise_session($exe_id)
    {
        if (!isset($_SESSION['current_exercises'])) {
            $_SESSION['current_exercises'] = array();
        }
        $_SESSION['current_exercises'][$exe_id] = true;
    }

    public static function delete_chat_exercise_session($exe_id)
    {
        if (isset($_SESSION['current_exercises'])) {
            $_SESSION['current_exercises'][$exe_id] = false;
        }
    }

    /**
     * Update attempt date
     * @param int $exeId
     * @param Datetime $last_attempt_date
     */
    public static function update_attempt_date($exeId, $last_attempt_date)
    {
        $exercice_attemp_table = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $exeId = intval($exeId);
        $last_attempt_date = Database::escape_string($last_attempt_date);
        $sql = "UPDATE $exercice_attemp_table SET tms = '".api_get_utc_datetime()."'
                WHERE exe_id = $exeId AND tms = '".$last_attempt_date."' ";
        Database::query($sql);
    }

    public static function getExerciseResult($trackExerciseInfo)
    {
        $TBL_EXERCICE_QUESTION 	= Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
        $TBL_QUESTIONS         	= Database::get_course_table(TABLE_QUIZ_QUESTION);
        $TBL_TRACK_EXERCICES    = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $TBL_TRACK_ATTEMPT		= Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $query = "SELECT attempts.question_id, answer
              FROM ".$TBL_TRACK_ATTEMPT." as attempts
                INNER JOIN ".$TBL_TRACK_EXERCICES." AS stats_exercices
                    ON stats_exercices.exe_id=attempts.exe_id
                INNER JOIN ".$TBL_EXERCICE_QUESTION." AS quizz_rel_questions
                    ON quizz_rel_questions.exercice_id=stats_exercices.exe_exo_id AND
                    quizz_rel_questions.question_id = attempts.question_id AND
                    quizz_rel_questions.c_id=".$trackExerciseInfo['c_id']."
                INNER JOIN ".$TBL_QUESTIONS." AS questions
                    ON questions.iid=quizz_rel_questions.question_id AND
                    questions.c_id = ".$trackExerciseInfo['c_id']."
              WHERE attempts.exe_id='".$trackExerciseInfo['exe_id']."' AND user_id=".intval($trackExerciseInfo['exe_user_id'])."
              GROUP BY quizz_rel_questions.question_order, attempts.question_id";

        $result = Database::query($query);

        $exerciseResult = array();
        while ($row = Database::fetch_array($result)) {
            $exerciseResult[$row['question_id']] = $row['answer'];
        }
        return $exerciseResult;
    }


    public static function getExerciseResults($exerciseId, $courseId, $sessionId)
    {
        $track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $exerciseId = intval($exerciseId);
        $courseId = intval($courseId);
        $sessionId = intval($sessionId);

        $sql = "SELECT DISTINCT e.exe_id, e.data_tracking
                FROM $track_exercises e INNER JOIN $track_attempt a ON (a.exe_id = e.exe_id)
                WHERE 	exe_exo_id 		= $exerciseId AND
                        a.c_id = $courseId AND
                        e.c_id = $courseId AND
                        e.session_id 	= $sessionId AND
                        status = ''";
        $result = Database::query($sql);
        return $result->fetchAll();
    }
}